Recent advances in light-emitting diode (LED) technology, including improvements in color accuracy, device longevity, energy efficiency, and manufacturing costs, have made LEDs a popular choice for many lighting applications. In particular, LED technology is commonly used in lighting applications where energy efficiency, size, and/or color accuracy are important. For example, in mobile applications, such as automotive and aeronautical applications, size and energy efficiency are important factors that are taken into account when choosing a lighting system.
Lighting systems that utilize LED technology typically use color mixing techniques to generate white light. For example, an LED lighting system may include red, green, and blue (RGB) LEDs, the output of which is mixed to generate light that is substantially white in appearance. In conventional lighting systems, RGB light is mixed to generate white light by projecting the light emitted by each of the RGB LEDs onto a surface that is a minimum distance away (e.g., 1 to 3 feet) away from the LED lighting module. When the surface onto which the light is projected is at least the minimum distance away from the LED lighting module, uniform white light may be achieved. However, when the light is projected onto a surface that is closer than this minimum distance, color mixing may be incomplete or non-uniform, resulting in color fringing and/or scalloping of the incident light. Such non-uniformities commonly prevent LED lighting modules from being separated from a target surface by a minimum distance required for light mixing.
Therefore, improved light mixing techniques would be useful for a variety of lighting applications and related devices.